Spray gun



Nov. 14, 1944. H. c. sTocKDALE SPRAY GUN Filed July 31, 1940 WSA/WP: wwwa fam/04a '/VEI/ h SN J Il, amg. mi.:

l tively high pressure.

Patented Nov. 1 4, 1944 SPRAY GUN Harry C. Stockdale,A Ravenna, Ohio,assignor to Food Machinery Corporation, San -lore, Cal a corporation ofDelaware Application July 31, 1940,y Serial `N0. 348,749

1 Claim.

This invention relates to spray guns and particularly to spray gunsoperating' under rela- `It is an object of this invention to provide anovel and eiiicient spray gun, the operation of which is relatively easyand which embodies K means forcontrolling the form of the spray producedthereby which can be manipulated without removing the hands from thegun.

It is also an object of this invention to provide a, spray gun having aliquid guiding and controlling device for controlling the formation of aspray which may be readily removed as a unit from the barrel of the gunfor the purpose of cleaning the same or replacing worn parts.

The manner of accomplishing'the aforesaid objects, 'as well as furtherobjects and advantages, will be made manifest in the followingdescription taken in connection with the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional view through a preferred embodimentof the spray gun of my invention, showing the trigger valve closed andthe spray control in a fine spray position.

Fig. 2 is a fragmentary view corresponding to the right hand half ofFig. l but illustrating the spray control mechanism positioned so' as tothrow a solid pencil-like stream of liquid from said gun.

Fig. 3 is a view similar to Fig. lof the handle portion of said gun,illustrating the operation of the trigger mechanism to crack the valveopen.

Fig. 4 is a view similar to Fig. 3 illustrating further opening of thetrigger valve after this has been cracked, as shown in Fig. 3.

Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 1 showingthe liquid straightening spider provided in the invention.

Fig. 6 is a cross-sectional view taken on the line 6--6 of Fig. 1 and afront elevational view of the whirl member of said spray gun.

i member Il is a liquid passage I3, there being a hose connection I4 atthe outer end of this for connecting a hose to the gun. Also provided inthe butt member Il to control the passage I3 is a valve I5 including avalve ball I6 which is urged against a seat I1 by a pressure spring I8and is adapted to be lifted from this se'a-t by a valve stem I9 whichenters the passage I3 through a packing gland 20.

The pistol grip l2 is hollow and has fulcrum pins 25 and 26, which aredisposed varying distance yfrom the stem I9, and a latch pin 21 on theopposite side of the stem therefrom. Mounted in the grip I2 is a trigger30 having slots 3| and 32 which receive the pins 25 and 26 respectivelyas clearly shown inrFigs. 1 3, and 4.

Pivotally mounted by a pin 33 on the trigger 30 is a latch 34 having ahook 35 which is adapted to be hooked over the pin 21- when the trigger30 is compressed so as to hold the valve I5 open. The position of thelatch 34 when thus latching the trigger open is shown in broken lines inFig. 4. The latch 34 is urged into the position in which it is shown infull lines in Figs. 1, 3, and 4 by a coil spring 36. Thus, if thetrigger 30 is com? pressed to open the valve I5 and while it iscompressed the latch 34 is rocked into the broken line' position 38shown in Fig. 4 and the trigger released, the latch will hold thetrigger in comp ressed position. In order to release the trigger 30 fromthe latch 34, it is now only necessary to press the trigger slightly,whereupon the spring 36 returns the latch to its full line position inthe drawing so that when the hand is again relaxed from the' trigger,the latter returns4 to its full line position shown in Fig. 1.

It is also to be noted that in operating the valve I5 by the trigger 30,the initial motion of the latter, which cracks the valve-that is, whichrst opens it against the pressure of liquid thereagainst--constitutes arotation of the trigger 30 about the pin 26,- thus giving a high degree`of leverage to the trigger in cracking ther valve. After. the valve iscracked, however, not so much pressureis necessary to further open it,and in order to get a considerable movement during subsequent swingingof the trigger 30, the

pinv 25 provides afulcrum for the trigger 3|) as soon as the lost motionprovided by the slot 3| is taken up. This situation is rst reached whenthe trigger is positioned as shown in Fig. 3, after which further inwardswinging of the trigger 30 gives a disproportionately large movement ofthe ball I6 of the valve I5 as shown in Fig. 4.

The spray gun I0 also includes a primary barrel 40 and a secondarybarrel 4I, adjacent ends of' which are connected in offset relation byan adapter 42. These barrels comprise cylindrical tubes which arerelatively long when compared with the inside diameter thereof.

The primary barrel 40 is secured to the butt member II so as tocommunicate with the iiuid sleeve 45 rotatably mounted on the barrel 45between the ring 44 and the butt member The sleeve 45 includes acylindrical quill 45, the space inside which is partially relieved by ashallow recess 41 formed in the barrel 40. 'I'he quill 45 has a frictiongrip covering 45 which may be -of corrugated rubber and a cylindricalcam 49 'in which a cam groove 50 is formed.

'I'he secondary barrel 4| has a nozzle member 60 screwed into its frontend, this nozzle member being of relatively small cross-section, theportion thereof of largest diameter being flush with the outer surfaceof the barrel 4I. The nozzle member 60 has a liquid whirling chamber .5Iwhich is of smallerv diameter than the interior of the barrel 4| and isconnected with this barrel'by a beveled fillet 52 provided on the innerend of the nozzle member 50. The chamber 5| has a tapered forward endwhich communicates with a narrow opening 53. The nozzle member 60 isformed with a nipple 54 which is threaded to receive a cap 55 whichcompresses a. disc 55 and a packing washer 61 against the front end ofthe nozzle, the disc 55 having a central aperture of a size suitable forparticular kinds of spraying operations for which it is desired tousetheglm I0.

The adapter 42 is provided with an opening having a packing gland 59which is concentric with the secondary barrel 4 I. Y

Longtudinally slidable in the secondary barrel 4| and self-guided by theinterior surface of said barrel so as to be axially centered therein atall times under various operating conditions, is a liquid guiding andcontrolling device 10. This control device includes an assembly andoperat.. ing shaft 1| which extends slidably through the gland 69 asshown in Figs. 1 and 2. The front end of this shaft is threaded into aliquid spreading and whirling head 12 having an expanding frusto-conicalouter surface 13 and a counterfrusto-conical surface 14 at its frontend, from which extends a tubular whirl sleeve 15. This sleeve hasformed therein a series` of slots 15, the latter lying in planes whichare parallel with the axis of the barrel 4| and equi-distant from saidaxis so that said slots 16 have a spiral relation to the axis of thebarrel.

. It is to be noted that the sleeve 15 is of such a diameter as toslidably fit into the chamber 6| when the device 15 is slid in arightward direc' tion in the barrel 4|. It is also to be noted that thefrusto-conical surface 14 is disposed substantially parallel to thefrusta-conical surface of the fillet 62 so that as the head 12 is movedto insert the sleeve 15 into the chamber 6| the annular passagewaybounded by the frusto-conical surface 14 and the iillet 62 is uniform inthickness at various points therein.

The liquid guide and control device includes a spider sleeve 80 having aseries of guide fins 8| preferably formed integrally therewith andextending outwardly to slic'iably engage with the inner surface of thesecondary barrel 4i. 'I'he spider 80 is rigidly fixed upon the shaft 1|as by a pin 82. Snugly pressed over the shaft 1I is a stop sleeve 85 forlimiting the rearward movement of the device 10.

Mounted on the rearwardly extending end of the shaft 1| is a camfollower nut 55 having a lug 81 which extends into the cam groove 55 ofthe cylindrical cam 49.

aseae Operation The gun I9 of this invention is adapted to be used fordirecting high pressure sprays with variable amounts of liquidand todeliver at option a rod-like stream of.` liquid. While applicable inmany arts, this invention is particularly useful in the cleaning ofautomobiles.

Control of the amount of liquid contained in the spray or rod-likestream projected from .the gun is accomplished by the size of orifice inthe disc 55. Turning the iiow onor of! is effected by the trigger 50.Control of the spread of the spray or the selective formation of arod-.like stream of liquid is accomplished by 'rotation of thecylindrical control sleeve 45. Thisrotation operates through thecylindrical cam 49 to push and pull aon the rod 1| and thus slide theentire liquid guiding and controlling device 10 axially in the secondarybarrel 4 I As already pointed out, the flns 8| of the spider sleeve 90of the device 10 bear againstthe inner surface of the barrel 4| andmaintain this device during said sliding movement at all times axiallyaligned with said barrel. This, of course, also y maintains the head 12and sleeve 15 in true axial alignment with the nozzle member 50 and thewhirling chamber 6| of the latter.

When the valve I5 is opened, by pressing on the trigger 35, the liquidrushes from the passage I5 through the barrel 40 and the adapter 42 intothe barrel 4|. In passing through the latter barrel, the liquid isguided by the guide fins @l causing this liquid to travel in pathsdisposed `lust inside of the barrel 4| and parallel with the axisthereof. .After traveling through the spaces batween the fins 8|, theliquid enters the annular space surrounding the head 12 where it passesthrough an increasingly restricted annular passageway 90, from which itflows as a tubular sheet of liquid into an annular space 9| which`isdisposed between the truste-conical face 14 and the reversefrusto-conical face of the fillet 52.

If the space 9| is opened up by the extreme rearward positioning of thedevice 10 as shown in Fig. 2, the liquid passes directly through thespace 9| and the nozzle chamber 5|' and out through the central aperturein the nozzle disc 66 as a rod-like stream. The stream is thus formedwith a high degree of efliciency, this being due to the axial directionimparted to the liquid as it travels between the guide fins 5| and thedistention of these streams into a single tubelike sheet of liquid bythe passage of these petween the head 12 and the barrel 4I. Thistubelike stream of liquid is caused to converge when it strikes thefillet 62, and enters the chamber 6| with a minimum of friction andturbulence and thus produces a maximum of pressure and dynamic energy inthe water occupying this chamber. This in turn produces a relativelyhigh velocity in the rod-like stream of liquid expelled through theaperture in the disc 65.

In order to change this rod to a spray, the operator rotates the sleeve45, thus propelling the guide and' control device 10 axially forwardlyin the barrel 4|. Fig. 1 shows this operation carried to the point wherea relatively fine spray will be emitted from the nozzle of the gun.

As the front end of the tubularwhirl sleeve 15 enters the cylindricalnozzle chamber 5|, the liquid which theretofore haspassed directly fromthe annular space 9| into the chamber 5|, is now forced to flow throughthe tangential slots 15 into the interior` of the sleeve 15 and thenceinto the chamber 6I. As the liquid enters this chamber after passingthrough the slots 18, itis whirling rapidly about the axis of the nozzle60 and forms itself into a whirling spray as it passes outwardly throughthe aperture in the disc 66.

It is to be noted that the slots 16 are formed in planes which areparallel with the axis of the liquid guiding and controlling device 10and are spaced uniformly from this axis, these slots being substantiallythe full length of the sleeve 15 and being uniformly pitched relative tothe axis of the head 12.

Attention is called to the fact that as the head 12 of the device 10 ismoved toward the nozzle member 60, after the sleeve 15 has once enteredthe chamber 6I, the eilectivel area of the slots 16 is graduallydecreased, yet at the same time the angle of the effective portions ofthese slots relative to the axis of the head 12 remains the same. Thus,although diierent quantities of liquid are admitted to the chamber 6Ifor the formation of the whirling spray by the'gun I0, a relativelyconstant whirling tendency is imparted to thisv liquid as it enters thischamber, so that the spray formed by the gun I0, no matter what itsintensity, is of substantially the same whirling character.

One of the important advantages of the present invention resides in theunitary character of the liquid guide and control device 10 whichpermits this to be assembled with and removed from the secondary lbarrelII of the spray gun as a unit for purposes of cleaning the same orreplacing parts which may have become worn. In some instances, also, itis desirable to place the head 12 in use at a given time with anothersimilar head having slots 15 which are differently pitched or of adifferent size. This may become necessary where the character of liquidto be handled by the gun I0 varies in density or viscosity, or wherevarying amounts of solid material may be entrained in the liquid handledby the gun.

In the present gun construction, it is to be noted that all of theoperating parts of the gun may be exposed to view for the cleaning ofthe same by the simple operation of unscrewing the secondary barrel 4Ifrom the adapter I2 and sliding this barrel oi of the guide and controldevice 10. In order to render this disassembly and re-assembly of thegun easy, a hex shoulder 95 is provided on the barrel II, which shoulderabuts against the adapter 42 when the barrel 4I is screwed into thelatter.

Another advantage of the spray gun oi' my in. vention is the ease withwhich it may be handled and controlled by the operator. This gun isdesignedto be carried in the two hands, the pistol grip I2 being grippedin the right hand and the sleeve 45 being gripped in theA left hand. Thehose is attached to the connection I4 which it is to be noted is abovethe pistol grip I2 so that when the hose is being pulled along by theoper-V ator of the gun it will tend to lift the gun instead of depressthis.

In the commercial uses for which the spray gun of my invention isdesigned it is necessary to be able to quickly alter from time to timethe character of the spray issuing from the nozzle of the gun. Itis-also necessary at frequent intervals to shut the gun off completelyand then recommence operations after a short pause. More often than not,it is desirable, when thus recommencing operations, to produce a sprayof the same character as was being .produced before the gun was shutoif. The spray gun I0 of my invention may be operated in this mannerwithout removing the hands from the gun, the function of turning on orshutting off the gun completely being effected by clinching the pistolgrip I2 in the right handso as to swing the trigger 30 inwardly thusopening the valve I5, or the releasing of this grip so as to allow thespring I8 to close this valve and swing the trigger forwardly. Theadjustment of the spray control device 10 is eiected by rotating theleft hand in which the sleeve45 is gripped.

The design of my spray gun is thus seen to be such that it can behandled so as to direct the spray wherever desired and controlled so asto determine the character of the spray and turn on or shut off the gunwithout removing the hands from the grips or shifting these in any wayfrom the positions in which the hands grip the gun.

I claim:

In a spray gun, the combination of: a primary tubular barrel; asecondary tubular barrel, the axis of which is offset from said primarybarrel; adapter means connecting adjacent ends of said barrels; nozzlemeans provided in the free end of said secondary barrel; nozzle controlmeans provided in said secondary barrel, said means including a rod foroperating said control means;

a stuillng box in said adapter means through which said rod passes; arotary grip provided on said primary barrel, there being a helicalthread provided on said grip; and means on the extending end of said rodfor engaging with said thread to permit said rod to be shifted axiallyby the rotation of said sleeve for the purpose of actuating said nozzlecontrol means.

U HARRY C. STOCKDALE.

